Anti-Inflammatory and Antioxidant Activities of Ethanol and Aqueous Leaves Extract of Trema guineensis

Abstract

Trema guineensis is a plant of Cote d’Ivoire which is widely used in folk medicine for the treatment of a variety of diseases such as malaria, anemia. We have tested the anti-inflammatory activity (inhibition of carrageenan induced paw edema, erythrocyte sedimentation test, concentration of Reactive protein-C), the in vitro antioxidant (DPPH radical essay and lipid peroxidation) and the in vivo antioxidant activities (FRAP, TBARS essay) of its ethanolic leaves extract as well as its aqueous leaves extract. The maximum inhibition (33.58%) was obtained with the ethanolic extract with the dose of 200 mg kg–1 b.wt. after 5 h of drug treatment in carrageenan induced paw edema, whereas diclofenac (used as the standard) produced 27.97% of inhibition. Reactive Protein-C (CRP) concentration indicated that the ethanolic extract (0.29±0.02 mg L–1) had more impact on the edema. This tendency was still observed with the erythrocyte sedimentation test. Linear regression analysis was used to calculate IC50 value. The results showed that, the ethanolic extract exhibited significant DPPH with IC50 value of 20.23±0.4 μmol mL–1 while, the aqueous extract inhibited with IC50 value of 12.3±0.09 μmol mL–1 in comparison to the control (vitamin C). Lipid peroxidation induced by the Fe2+, was inhibited more by the ethanolic extract. The in vivo study in rats with the extracts showed a significant antioxidant activity using the FRAP and TBARS methods. The ethanolic extract values (11.77±0.33% and 730±5.00 μmol of iron II/L) were the best compared to the vitamin C (reference molecule). These observations helped us to conclude that the ethanolic and aqueous extracts are endowed with interesting anti-inflammatory and antioxidant activities; in addition, the ethanolic extract (200 kg mg–1 b.wt.) was most active. The phenols, the flavonoids and the flavonols may play an important role in these activities.